Season each veal cutlet with salt, pepper, and garlic powder. On each of four of the cutlets, place 1 slice of cheese, 2 spears of asparagus, one slice of prosciutto, and another slice of cheese on top. Top each stack with a second cutlet, folding under and pressing the edges together to make a package.
In a shallow bowl, whisk together egg and milk. Place the bread crumbs on a plate. Dredge both sides of the veal packages in flour. Dip each one in the egg mixture, then coat with bread crumbs. Place on a plate, and refrigerate for 30 minutes.
Preheat the oven to 350 degrees F (175 degrees C). Heat olive oil in a large cast-iron skillet over medium-high heat. The skillet should be large enough to hold all four packages. Brown the veal on both sides, about 5 minutes per side. Add the onion and red peppers, and cook over medium heat until they are translucent. Pour in the wine, and simmer until the alcohol has cooked away - it will no longer smell as strongly. Pour in the chicken broth, and add the mushrooms.
Place the skillet and its contents into the preheated oven, and bake for about 30 minutes, or until the internal temperature of the veal has reached 160 degrees F (70 degrees C). The sauce should also be reduced by about half.
